When I start to work on a photo on my computer, one of the first things I look at is the Levels histogram. I use Photoshop Elements, but all photo editing software programmes will have a way of doing this adjustment in one of their menus.
A properly exposed photograph should normally contain a full range of tones from white through to black. Of course, this won’t apply in every situation – you wouldn’t expect a photograph of a snowy landscape to contain a full range of dark tones within it. So for the purposes of this blog, we’ll assume that we’re photographing a scene with a normal range of light and dark colours in it.
Once you’ve opened your photo in your editing programme, go into the Levels menu and look at the histogram. A histogram is a bar graph looking rather like a black mountain, and underneath the histogram are three sliders, black on the left edge, grey in the middle, and white on the right edge. If the edges of the black mountain don’t reach as far as the black or white arrows, then adjustments can be made to increase the contrast in the image.
Make sure the preview box is checked and then slide each pointer in until it reaches the edges of the black histogram. You may decide to go just part of the way in rather than the whole way, depending on the type of image. When you’re happy with how it looks, click okay.
As well as or instead of the above, the grey slider can be moved to left or right to lighten or darken the mid-tones in the image.
Above left is before levels adjustments and above right is after. The pic at the top of this blog has also had tweaks of colour saturation and colour temperature.
Don’t feel though that every photo should have the full range of tones from black to white – sometimes you may want a more subtle, soft effect, or a purposely high-key or low-key image. But the levels tool can be great for giving a bit of life and impact to a rather flat or insipid original.